1,1,1,2,3,3,3-Heptafluoropropane, also called heptafluoropropane, HFC-227 or HFC-227ea (ISO name), is a colourless odourless gaseous halocarbon. It is commonly used as a gaseous fire suppression agent.

Chemistry

Its chemical formula is CTemplate:Fluorine3-CHF-CF3, or C3HF7. With a boiling point of -16.4 °C, it is a gas at room temperature. It is slightly soluble in water (260 mg/L).

Use

HFC-227ea finds use in fire suppression systems in data processing and telecommunication facilities, and in protection of many flammable liquids and gases. Effective fire suppression requires introducing 7% concentration of the HFC-227ea agent. Its NOAEL level for cardiac sensitization is 9%. The United States Environmental Protection Agency allows concentration of 9 volume% in occupied spaces without mandated egress time, or up to 10.5% for a limited time. Most fire suppression systems are designed to provide concentration of 7-11%.

The HFC-227 fire suppression agent was the first non-ozone depleting replacement for Halon 1301. In addition, HFC-227 leaves no residue on valuable equipment after discharge.[2]

HFC-227ea contains no chlorine or bromine atoms, presenting no ozone depletion effect, but its global warming potential is quite high. Its atmospheric lifetime is approximated between 31 and 42 years. It leaves no residue or oily deposits and can be removed by ventilation.

As an aerosolpropellant, HFC-227ea is used in pharmaceutical metered dose inhalers such as those used for dispensing asthma medication.

Safety

At high temperatures, heptafluoropropane will decompose and produce hydrogen fluoride. This is observable as presence of sharp, pungent odor, which can be perceived in concentrations far below a dangerous level. Other decomposition products include carbon monoxide and carbon dioxide. Prior to re-entry of a room where HFC-227 system has been activated to suppress a fire, the atmosphere should be tested.